Tuesday, March 13, 2012

this week's MGRE Math Beast Challenge

In a school of x students, 36 are in the honors program, and x% of the 35 female students are in the honors program. If 15 male students are in the honors program, what fraction of all the non-honors students are female?

1 comment:

I did this somewhat hastily, so I admit I might be wrong, but I think the answer is (B), 7/12.

With all such problems, it's a good idea to list what you know, and also what you can immediately deduce from the givens. Here's what I scribbled:

x = total # students (given)36 = total # honors students (given)15 = total # male honors students (given)21 = total # female honors students (deduced)35 = total # female students (given)x - 35 = total # male students (deduced)

The same "x" is used as a percentage: "x% of the 35 female students are in the honors program." Whatever that x% is, I already know the raw number of female honors students is 21, something I quickly deduced. So I can set up an equation: